Grandstream Networks GHP6 Series Administration Manual page 26

SDP Bandwidth Attribute
H.264 Payload Type
Packet Retransmission
Enable BFCP
Initial INVITE with
Media Info
Presentation H.264 Image
Size
Presentation H.264
Profile Type
Presentation Video Bit
Rate
Presentation Video Frame
Rate
BFCP Transport Protocol
SRTP Mode
high that causes no video or video quality issue during video call. In this case, please change "H.264 Image
Size" to "VGA" or "CIF" and change "Video Bit Rate" to "384kbps" or lower.
Sets the SDP bandwidth attribute. It can be selected from the drop-down list. The default setting is "Media
Level".
● Standard: use AS format in session level; use TIAS format in media level
● Media Level: use AS format in media level.
● Session Level: use AS format in session level.
● None: no modifications in the session format.
Note: Please do not modify this setting without knowing the session format supported by the server.
Otherwise, it might cause video decoding failure.
Specifies the H.264 codec message payload type format. The default setting is 99.
The valid range is from 96 to 127.
Presentation Settings
If set to "NACK", the signaling will carry NACK info. After negotiation, the media will use NACK to
retransmit lost packets. If set to "NACK+RTX (SSRC-GROUP)", the signaling will carry both NACK and
RTX info. After negotiation, the media will use NACK+RTX (SSRC-GROUP) to achieve packet loss
retransmission. If set to "Disabled", packet loss retransmission cannot be used.
The Default setting is "NACK+RTX (SSRC-GROUP)".
If set to "Yes", the device will be able to receive the presentation stream in video calls and video meetings.
Initial INVITE SDP contains presentation media.
Selects the H.264 image size. Users can select 1080P or 720P.
Select the Presentation H.264 Profile Type from "Baseline Profile", "Main Profile", "High Profile" and
"BP&MP&HP". The default setting is "BP&MP&HP".
The lower the profile type is, the easier the packet can be decoded. However, higher level has high
compression ratio. For device with low CPU, select "Baseline Profile" to play record; "Baseline Profile" is
more likely to be used in a video conference that has high demanding for the video quality. Select among the
three types to achieve best video effect.
Configures the bit rate of the video. The video bit rate can be adjusted based on the network environment.
Increasing the video bit rate may improve video quality if the bandwidth is permitted. If the bandwidth is not
permitted, the video quality will decrease due to packet loss. Video Bit Rate can be set to integer value from
512kbps to 2048kbps.
Configure the video frame rate for presentation.
Defines the transport protocol used for BFCP. Users can choose from Auto/UDP/TCP. The default setting is
"UDP" first, if not supported, then choose "TCP". If choose "Auto", automatically switches between "UDP"
and "TCP".
RTP Settings
Sets if the phone system will enable the SRTP (Secured RTP) mode. It can be selected from dropdown list:
● Disable
● Enabled but not forced
● Enabled and forced
SRTP uses encryption and authentication to minimize the risk of denial of service. (DoS). If the server
allows to use both RTP and SRTP, it should be configured as "Enabled but not forced". The default setting is